In machine processing of metallic articles, an oily liquid or grease is applied over the articles in order to improve their machinability and also in order to prevent them from rusting. Such oily substances must be removed during machining or after machining has been completed.
This invention relates to a method for removing such oily substances from metallic articles, in which the substances are evaporated by heating the metallic articles so that the oily substances are removed from the metallic articles to such extent that such removal may not have trouble in further machining the articles.
Although oily substances of the kind mentioned above have been heretofore washed and removed by organic solvents such as tricholoroethylene, other removal methods have been sought, because the employment of such organic solvents is not desirable in view of environmental protection.
While oily substances have been heated so that they evaporate to air from metallic articles, other removal methods have been sought, because such evaporation to air damages working environment. There is also a risk that an oily gas removed from a metallic article by evaporation ignites and explodes.
It is therefore an object of this invention to provide a method by which oily substances can readily be removed without the employment of organic solvent and without a risk of explosion.